termining,
independently of experience, any particular event. We observe that B
follows A, but, for all we can say, it might as well follow any other
letter of the alphabet. Yet we are entitled to say in general that it
does uniformly follow some particular letter. The metaphor which
describes cause and effect as a 'bond' tying A and B together is
perfectly appropriate if taken to express the bare fact of
sequence;[476] but we fall into error if we fancy there is really any
bond whatever beside the events themselves.

The belief, then, in causation has precisely the same import according
to Hume and Brown; and both agree that it is not produced by
'reasoning.' The proposition 'B has once succeeded A,' or 'has
succeeded A a thousand times,' is entirely different from the
proposition 'B will for ever succeed A.'[477] No process of logical
inference can extract one from the other. Shall we, then, give up a
belief in causation? The belief in any case exists as a fact. Hume
explains it by custom or association. Brown argues, and I think with
much force, that Hume's explanation is insufficient. Association may
explain (if it does more than restate) the fact that one 'idea' calls
up another idea, but such association may and often does occur without
suggesting any belief. The belief, too, precedes the association. We
begin by believing too much, not too little, and assume a necessary
connection of many phenomena which we afterwards find to be
independent. The true answer is therefore different. There are three
sources of belief, 'perception,' 'reasoning,' and 'intuition.'[478]
Now, we cannot 'perceive' anything but a present coincidence; neither
can we establish a connection by any process of 'reasoning,' and
therefore the belief must be an 'intuition.' This, accordingly, is
Brown's conclusion. 'There are principles,' he says, 'independent of
reasoning, in the mind which save it from the occasional follies of
all our ratiocinations';[479] or rather, as he explains, which
underlie all reasoning. The difference, then, between Hume and Brown
(and, as Brown argues, between Hume and Reid's real doctrine) is not
as to the import, but as to the origin, of the belief. It is an
'intuition' simply because it cannot be further analysed. It does not
allow us to pass a single step beyond experience; it merely authorises
us to interpret experience. We can discover any actual law of
connection between phenomena only by observing that they o